Pointing devices of various types are used in almost every computer application today. Some of the pointing devices that have been developed and popularized include:
(1) a mouse;
(2) a trackball;
(3) a transparent-touch screen that overlays the display including resistive and capacitive types;
(4) pressure, capacitive, resistive, or thermal sensitive tablet separate from the display;
(5) beam-breaking detectors surrounding the display;
(6) a light pen based on detection of the raster scan timing of the phosphor refresh beam;
(7) a stylus that incorporates pressure transducers; and
(8) a pen using ultrasonic, stereo tactic or radio frequency triangulation methods.
The various devices developed to position a pointer on a computer screen operate in conjunction with the application software on the computer using an appropriate software driver. Most such drivers try to emulate the conventional X/Y roller mouse. Typically, only positional information is fed to the application software that controls the position of the pointer on the screen.
Pens may offer increased fidelity of user interaction with computer systems. However, depending on implementation, the resolution of pen position determination may be limited to that of the touch-sensitive sensor. Often, touch screens and tablets have a touch resolution that is coarser than the screen resolution of the computer for which they are acting as an input device.